The invention relates to a method and a device for segmenting a digital image of biological cells, a method and a device for analyzing the dynamic behavior of biological cells and a method and a device for visualizing the dynamic behavior of biological cells.
Measuring the movement of biological cells is used as a screening method in the search for pharmacological agents, for example in tumor and immunology research, thus providing an in-vitro alternative to animal experiments.
In one known method, the cells are dyed with fluorescent dyes using suitable techniques to make it easier to distinguish between the cells and the background or environment. The disadvantage of this technique is that the physiology of the cells may be affected by the dye, particularly the mobility and motion of the cells, meaning properties that are to be studied. The known method is essentially limited to a two-dimensional sample, such as a cell lawn, for example, because preparing three-dimensional samples would be very complex. Furthermore, adding the third dimension is very complex in terms of the technical equipment required, in that an automatic motorized microscope is needed and large amounts of data are generated that make routine applications difficult. In the case of long-term experiments, especially, problems result from the fact that the fluorescent effect changes over time due to decomposition or deposition in certain cellular components. If a tagged cell divides during observation, it is not possible to ensure that the tag is passed on equally to both daughter cells.
Conventional methods for cell tracking make assumptions about cell properties, such as their shape or size, which are assumed to be constant. However, these assumptions cannot be maintained for all cell types, and especially not for mobile cells. In addition, these methods are either very complex with regard to the hardware or computing power required and/or are very sensitive to any blurred demarcations between the cell and its environment. Especially in three-dimensional samples of cells in a heterogeneous collagen matrix, these demarcations are not present to a sufficient extent.
The object of the invention is to specify a method for segmenting a digital image of biological cells that involves minimal technical requirements, does not necessitate any special preparation or manipulation of the cells to be observed and which requires as few assumptions as possible to be made about the properties of the cells.